The objective of the proposed research is to develop a method for providing fast and accurate measurements of volume and ejection fraction from 3D echo images. Our Computer Aided Measurement System will reconstruct the LV endocardium using a few user selected points on oriented echocardiographic images together with prior shape and size knowledge. The Specific Aims for Phase I are: 1. To improve the accuracy of quantitative echo while minimizing manual labor. 2. To improve the ease of use of the prototype system for application in a clinical setting. 3. To expand the catalog representing our knowledge base by acquiring additional large volume and abnormally shaped LV's in order to enhance fitting accuracy for atypical shapes. Previously described methods of analyzing echocardiograms in 3D require so much manual labor that this modality has been limited to research applications. The advantages of our proposed approach are that it makes the superior accuracy and reproducibility of 3D echo available for clinical practice. Furthermore this process will be applicable to other imaging modalities. PROPOSED COMMERCIAL APPLICATIONS: This research will lead to products which can be sold to echocardiography system manufacturers and end users. The products will provide accurate and convenient value measurements.